I'm not a medical scientist, so cannot speak to the physiological aspects of the argument, but there is a flaw in the basic scientific logic used in the argument. Namely, that if cancer in humans is due to exposure to airborne radionucliides and not cigarrette smoke, then why do none of the rats and mice in the purported laboratory studies also get cancer from the same radionucliides? Are all lab rats and mice exposed only to filtered air and cigarrette smoke? I doubt it.
A basic flaw in scientific reasoning such as this casts serious doubt on the whole concept. It makes me skeptical about all of the other alleged "data" presented.
It is my understanding, based on discussions I have had with toxicologists (people who study how poisons kill you) I work with (in the haz-waste cleanup business), that cancer risk is evaluated to a large extent by statistical analysis of large populations. In other words, studies are done of how many people who smoke get cancer compared to how many people who don't smoke get cancer. And the numbers I have seen are overwhelming.
Did Dr Schrauzer happen to be an employee of the cigarrette industry? (grins)
Do radionucides from testing exacerbate the effects of smoking in causing cancer? Could be.
I'd suggest looking at some reputable publications to get your science, for example, Science News.